Known torque limiters generally are of two types, i.e., a friction type and an interlocking claw or jaw type, and are subject to several shortcomings which make use of the same undesirable in many applications. Particularly, the friction type torque limiter commonly employs cooperating, spring-loaded friction surfaces for torque transmission with overload torques causing the friction surfaces to slip relative to one another. Such torque limiters are subject to premature and detrimental wear and require frequent adjustment depending on environmental conditions and wear of the friction surfaces to maintain accurate torque limiting control. The jaw type torque limiter employs as torque transmitting elements spring-loaded interlocking tapered jaws which are urged axially apart by the driving torque to disconnect the input and output on overload. In some designs, the tapered jaws are replaced by spring-loaded balls which are driven by excessive torques from indentations in cooperating elements or races. Such type of torque limiter is also subject to premature or undesirable wear particularly under high speed and continuous slip conditions. In any event, the torque limiters usually must be mounted on the low speed side of the drive train, and further, not all such limiters are bi-directional as often is desirable. Moreover, such torque limiters act as relatively rigid couplings at torques below overload and shock loads at such lower torques are transmitted through the torque limiter.
Accordingly, use of known torque limiters in limited or restricted, and such known torque limiters are subject to premature wear particularly under high speed and continuous slip conditions.